Probably has already been asked... Remote commands

I'm sure this has been asked but I need clearification. I would like to create a script that can run remote programs and edit remote files on Linux (both hosts are linux). The reason is I would like to make a web hosting control panel using PHP that I can have my mail & dns server on one machine and web on the other. Is there any way possible to do this with PHP? I searched the arhives and found something about ssh_agent but couldn't find a lot of information from google. Any help would be appreciated. I have php experience just not very much... Anything would be appreciated! Thank You Richard Marriner II